An open source web server and web application scanner that tests for misconfigurations, bugs, and missing patches. Not designed to be subtle, it's a pen tester's auditing tool through and through.
Determines what version of a web app that it already knows about is run by comparing hashes of certain files with precomputed hashes from known versions. Designed to be low-bandwidth, fast, and automatable. Runs as a stand-alone tool or can be included as a Python module in other software.